Table 1 .--The germination of ponderosa pine seeds stratified in the laboratory on a 

 variety of seedbeds with different fungal control measures. 



Treatment^ : 









Seedbed 









Seedbed : Seed : 



Duff 



Litter 



: Litter : 

 : and duff : 



Opening : 

 topsoil : 



Canopy 

 topsoil 



: Silica 



: Average 











Percent- - - 









-- 



80.2 



84.3 



87.8 



88.3 



88.4 



81.4 



85. 1 

 2±9.2 



A 



87.1 



88.7 



88.7 



83.5 



87.5 



84.8 



86.7 

 ±4.8 



F 



90.2 



91.1 



87.2 



82.5 



84.8 



90.5 



87.7 

 ±7.8 



A F 



87.0 



77.4 



81.8 



82.4 



83.2 



76.6 



81.4 

 ±8.6 



Average 



86.1 



±7.3 



85.4 

 ±10.4 



86.4 

 ±5.4 



84.2 

 ±4.8 



86.0 

 ±4.2 



83.3 

 ±10. 1 





^A = Autoclaved, F = Fun] 

 2 ± Standard Deviation 



gicide 













plant material were 



more 



heavily 



infected than 



the topsoil 



seedbeds , 



and the 



silica 



could not support a fungus because of insufficient nutrients. The combined autoclaved- 

 fungicide seedbeds were probably contaminated by fungal spores introduced with the 

 seeds. In general, all seedbeds that were autoclaved had a heavier fungal growth than 

 those that were not. This may have been due to the elimination of competing bacterial 

 and fungal populations, the breakdown of a fungicidal compound in the seedbed during 

 autoclaving, or the release of nutrients by autoclaving. 



The seedcoat fungicide was quite effective in eliminating seedcoat contamination 

 when the seedbeds were not autoclaved. The fungicide was probably less effective in 

 the autoclaved seedbeds because of the larger fungus populations in these dishes. 



Table 7 shows that within any one seedbed there was essentially no difference in 

 germination between any of the treatment groups. Consequently, the results for the 

 treatments within each seedbed were averaged and compared. When this was done, it be- 

 came obvious that there was no difference in germination due to the seedbed on which 

 the seeds were stratified. 



Similar results were obtained by comparing the germination of seeds from different 

 seedbeds that had received the same treatment. Again, there were no differences, so 

 the results for the six seedbeds were averaged within each treatment and then compared. 

 No differences were observed in germination between treatments. 



Unlike the field experiment, no seedbed in the laboratory hindered the germination 

 potential of the ponderosa pine seeds. The absence of fungus on the seedbed (silica 

 seedbed] or the absence of fungus on the seedcoats (seedcoat fungicide treatments) did 

 not improve the germination, or conversely, the presence of fungus did not significantly 

 reduce germination. 



18 



